1. Field of the Invention
The present invention relates to a touch-sensing substrate, and more particularly, to a touch-sensing substrate which may be integrated into a color filter substrate or a touch sensing liquid crystal display.
2. Description of Related Art
With the rapid development and application of information technology, wireless mobile communication, and informational household appliances, a good number of informational products are now using a touch panel as an input device instead of a conventional input device such as a keyboard or a mouse, wherein a touch-sensing display has become one of the most popular products on the current market.
Current touch panels mainly include capacitive, resistive, photosensitive touch panels with capacitive touch panels being the main stream product. Categorizing in terms of structure, touch panels may be divided into two major types, an attachment type and an integration type. Manufacture of the integrated touch panel can be combined with the fabrication process of the whole panel (e.g. the fabrication process of a color filter) and thus may help reduce overall thickness of the product to meet the trend of thin and light weight products.
In detail, an integrated capacitive touch panel structurally includes a single side design of integrating a color filter layer and a touch-sensing unit on one surface of a glass substrate as well as a dual side design of respectively fabricating the color filter layer and the touch-sensing unit on two opposite surfaces of the glass substrate. The dual side design is easier in fabrication but has limitation in terms of thickness and resolution. The single side design provides simpler structure than the dual side design but also has the problems of complicated fabrication and low resolution.
In general, in a touch panel of the dual side design, a capacitive sensing layer includes a transparent conductive layer of Indium Tin Oxides (ITO) and layers of insulating material, for example. However, thickness of the capacitive sensing layer easily affects overall transmittance of the color filer substrate. Therefore, to increase the transmittance of the touch panel in the above-mentioned dual side design, the thickness of the conductive film layer (e.g. the above-mentioned ITO) comprising the capacitance sensing layer usually has to be reduced. The aforesaid method, however, increases the sheet resistance of the conductive film layer in the capacitive sensing layer and thereby reduces the strength of sensing signals. Furthermore, the touch panel of the single side design in the conventional technology also encounters the same problem.
In other words, one issue to be resolved in the manufacturing technology of touch panels lies in how to appropriately reduce the thickness of the conductive layer without significantly increasing the sheet resistance so as to promote touch-sensing characteristics and transmittance of the touch panels.